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This article addresses the challenge posed by the Emerald Ash Borer (EAB), a wood–boring insect that threatens to kill ash trees, one of the North America's most vital tree genera. Current strategies include monitoring, treatment, and removal. However, the absence of a private-public partnership hinders progress on private ash trees. We propose two cost-sharing programs where local governments reimburse landowners for their management costs. This approach considers the EAB's dynamic growth over two periods based on different treatment decisions. Two mathematical models are developed for designing reimbursements: one based on the number of infested trees and another on the number of treated trees. We derive analytical solutions for the optimal treatment decisions and reimbursements in the first period. Our study reveals that treatment effectiveness and the likelihood of new infestations in the second period influence the optimal decisions. Comparing the reimbursement models, the treatment-based program proves more effective, encouraging landowners to treat more trees with higher reimbursements and overall benefits. Further, we show that continuing EAB treatment beyond the 2-year cost-sharing program is expected to yield superior long-term benefits. The approach seeks to foster private-public partnerships in addressing environmental challenges through resource sharing, such as managing water, land, and wildfires. [ABSTRACT FROM AUTHOR]

We estimate the value of information to farmers from a soybean rust sentinel plot monitoring network. Monitoring provides value over time from farmers learning about their risk of infection and contemporaneously from farmers making more profitable fungicide applications. Optimizing the spatial configuration of the network reveals the value of information plateaus at around $920 million with around 75 sentinel plots. The optimal spatial distribution of sentinel plots differs substantially from historical placements. Optimal sentinel plot placement would have included fewer plots in the Southern United States, where the risk of infection is relatively high, and more in the Midwest, where soybean production is relatively high. [ABSTRACT FROM AUTHOR]

Protecting wildlife within areas of resource extraction often involves reducing habitat fragmentation. In Canada, protecting threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) populations requires preserving large areas of intact forest habitat, with some restrictions on industrial forestry activities. We present a linear programming model that assesses the trade-off between achieving an objective of habitat protection for caribou populations while maintaining desired levels of harvest in forest landscapes. The habitat-protection objective maximizes the amount of connected habitat that is accessible by caribou, and the forestry objective maximizes net revenues from timber harvest subject to even harvest flow, a harvest target, and environmental sustainability constraints. We applied the model to explore the habitat protection and harvesting scenarios in the Cold Lake caribou range, a 6726 [km.sup.2] area of prime caribou habitat in Alberta, Canada. We evaluated harvest scenarios ranging from 0.1 [Mm.sup,3] * [year.sup.-1] to maximum sustainable harvest levels over 0.7 [Mm.sup,3] * [year.sup.-1] and assessed the impact of habitat protection measures on timber supply costs. Protecting caribou habitat by deferring or reallocating harvest increases the timber unit cost by Can$1.1-2.0 [m.sup.-3]. However, this impact can be partially mediated by extending the harvest to areas of oil and gas extraction to offset forgone harvest in areas of prime caribou habitat. Key words: caribou recovery, network flow model, mixed-integer programming, Steiner network, landscape connectivity, harvest scheduling model I, wildlife habitat protection, Canada. La protection de la faune dans les zones ou on procede a l'extraction des ressources implique souvent la reduction de la fragmentation de l'habitat. Au Canada, la protection des populations de caribou des bois (Rangifer tarandus caribou (Gmelin, 1788)) exige la preservation de vastes zones d'habitat forestier intact et l'imposition de certaines restrictions sur les activites forestieres industrielles. Nous presentons un modele de programmation lineaire qui permet d'evaluer le compromis entre la realisation des objectifs de protection de l'habitat pour les populations de caribou tout en maintenant les niveaux souhaites de recolte dans les paysages forestiers. L'objectif de protection de l'habitat maximise la quantite d'habitat non fragmente accessible au caribou et l'objectif de la foresterie maximise les revenus nets provenant de la recolte de bois, sujets a un volume regulier de recolte, une cible de recolte et a des contraintes de durabilite environnementale. Nous avons applique le modele pour explorer des scenarios de protection de l'habitat et de recolte dans le territoire du caribou du lac Cold, un excellent habitat pour le caribou d'une superficie de 6726 [km.sup.2] situe en Alberta au Canada. Nous avons evalue des scenarios de recolte variant de 0,1 [Mm.sup.3] * [an.sup.-1] a des niveaux maximum de recolte durable de plus de 0,7 [Mm.sup.3] * [an.sup.-1] et nous avons evalue l'impact des mesures de protection de l'habitat sur les couts d'approvisionnement en bois. La protection de l'habitat du caribou par le report ou la reaffectation de la recolte augmente le cout unitaire du bois de 1,1 a 2,0 Can$ [m.sup.-3]. Cependant, on peut en partie attenuer l'impact en etendant la recolte aux zones d'extraction d'huile et de gaz pour compenser la recolte perdue dans les zones qui offrent un habitat ideal pour le caribou. Mots-cles : retablissement du caribou, modele de flux de reseau, programmation partiellement en nombres entiers, reseau de Steiner, connectivite des paysages, modele de calendrier de recolte I, protection de l'habitat faunique, Canada., Introduction Woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) is designated a threatened species under Canada's Species at Risk Act (SARA) and Alberta's provincial Wildlife Act (Committee on the Status of [...]